SGBTRS(l) ) SGBTRS(l)
SGBTRS - solve a system of linear equations A * X = B or A' * X = B with a general band
matrix A using the LU factorization computed by SGBTRF
SUBROUTINE SGBTRS( TRANS, N, KL, KU, NRHS, AB, LDAB, IPIV, B, LDB, INFO )
INTEGER INFO, KL, KU, LDAB, LDB, N, NRHS
INTEGER IPIV( * )
REAL AB( LDAB, * ), B( LDB, * )
SGBTRS solves a system of linear equations A * X = B or A' * X = B with a general band
matrix A using the LU factorization computed by SGBTRF.
TRANS (input) CHARACTER*1
Specifies the form of the system of equations. = 'N': A * X = B (No transpose)
= 'T': A'* X = B (Transpose)
= 'C': A'* X = B (Conjugate transpose = Transpose)
N (input) INTEGER
The order of the matrix A. N >= 0.
KL (input) INTEGER
The number of subdiagonals within the band of A. KL >= 0.
KU (input) INTEGER
The number of superdiagonals within the band of A. KU >= 0.
NRHS (input) INTEGER
The number of right hand sides, i.e., the number of columns of the matrix B. NRHS
AB (input) REAL array, dimension (LDAB,N)
Details of the LU factorization of the band matrix A, as computed by SGBTRF. U is
stored as an upper triangular band matrix with KL+KU superdiagonals in rows 1 to
KL+KU+1, and the multipliers used during the factorization are stored in rows
KL+KU+2 to 2*KL+KU+1.
LDAB (input) INTEGER
The leading dimension of the array AB. LDAB >= 2*KL+KU+1.
IPIV (input) INTEGER array, dimension (N)
The pivot indices; for 1 <= i <= N, row i of the matrix was interchanged with row
B (input/output) REAL array, dimension (LDB,NRHS)
On entry, the right hand side matrix B. On exit, the solution matrix X.
LDB (input) INTEGER
The leading dimension of the array B. LDB >= max(1,N).
INFO (output) INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
LAPACK version 3.0 15 June 2000 SGBTRS(l)